KR101461022B1 - Display device, and method of driving the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a driving method thereof that can solve the problem of dark lighting failure of a liquid crystal display device.

A liquid crystal display device according to the present invention includes a liquid crystal display panel, a gate driver for driving gate lines of the liquid crystal display panel, a data driver for driving the data lines of the liquid crystal display panel, An LED lighting unit that emits light when the light source of the light source is turned on and emits light for a few seconds from a point of time when the backlight on signal supplied to the light source is supplied, and a backlight on / off signal for driving the light source A light source driving unit for supplying the light source and the LED lighting unit, and a TV system for supplying a driving voltage to the power source and the LED lighting unit, the voltage required for each of the liquid crystal display panel, the gate driving unit, and the data driving unit .

A counter unit, a timing controller, an LED lighting unit

Description

DISPLAY APPARATUS AND METHOD OF DRIVING THE SAME [0002]

The present invention relates to a display device and a driving method thereof that can solve the problem of dark lighting failure of a display device.

A liquid crystal display displays an image by adjusting the light transmittance of a liquid crystal having dielectric anisotropy using an electric field. To this end, a liquid crystal display device includes a liquid crystal display panel in which pixel regions are arranged in a matrix form, a driving circuit for driving the liquid crystal display panel, and a lamp for providing light to the liquid crystal display panel.

In a liquid crystal display panel, a plurality of gate lines and a plurality of data lines are vertically crossed with each other to define pixel regions. The thin film transistor formed at the intersection of each gate line and the data line is turned on according to the scan signal of the gate line to apply the data signal of the data line to each pixel electrode.

The driving circuit includes a gate driver for driving the gate lines of the liquid crystal display panel, a data driver for driving the data lines, a timing controller for controlling the driving timings of the gate driver and the data driver, And a power supply unit for supplying necessary power supply signals.

Such a liquid crystal display device is used in a versatile manner. In particular, an LCD TV can be realized by connecting a liquid crystal display device and a television (TV) system through a connector. At this time, the LCD TV includes an LED (Light Emitting Diode) lighting unit that emits light within a few seconds at the time of initial operation to solve the problem when the lamp is turned on.

On the other hand, when a discharge voltage is applied to the electrodes at both ends of the lamp, a plasma discharge occurs and light is emitted, and the LED lighting unit must operate for at least 3 seconds before being excited.

However, when the lamp and the LED lighting unit receive the driving voltage from the TV system, the lamp and the LED driving unit are operated from that point of time, so that the LED lighting unit can not be controlled in accordance with the lighting time of the lamp.

Accordingly, until the lamp emits light, the LED lighting unit must operate for a certain period of time, and dark lighting failure occurs.

SUMMARY OF THE INVENTION The present invention provides a display device and a method of driving the same that can solve the problem of dark lighting failure of a display device.

According to an aspect of the present invention, there is provided a display device including a liquid crystal display panel, a gate driver for driving a gate line of the liquid crystal display panel, a data driver for driving a data line of the liquid crystal display panel, A light source for emitting light to the liquid crystal display panel, an LED lighting unit for emitting light when the light source is turned on in a dark state and emitting light for a few seconds from a time of receiving a backlight on signal to be supplied to the light source, A light source driving unit for generating a backlight on / off signal and supplying the backlight on / off signal to the light source and the LED lighting unit, a power supply unit for supplying a voltage required for each of the liquid crystal display panel, the gate driving unit and the data driving unit, And a television system for supplying a driving voltage to the television system.

According to an aspect of the present invention, there is provided a method of driving a display device, including: supplying a driving voltage from a TV system to a light source driving unit and a power source unit; supplying an LED on signal generated from the power source unit to an LED lighting unit Supplying a backlight-on signal received from the light source driving unit to the counter, supplying a counter control signal counted for a few seconds from the time when the backlight-on signal is supplied to the LED lighting unit, The LED lighting unit is operated for a few seconds from the point of time when the LED is turned on.

A display apparatus and a driving method thereof according to the present invention supply a backlight-on signal generated from a light source driving unit supplied with a driving voltage from a TV system to an LED lighting unit. That is, the LED lighting unit is operated for several seconds from the time when the backlight on signal is supplied. Accordingly, defective dark lighting can be improved by operating the LED lighting unit until the lamp emits light.

Also, the display device and the driving method thereof according to the present invention can constitute a simple circuit configuration by using only LEDs, LED switching transistors, and resistors without using various passive elements and active elements.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 3. FIG.

1 is a block diagram of a liquid crystal display device according to an embodiment of the present invention. FIG. 2 is a block diagram of an LED lighting unit and an LED lighting unit according to an embodiment of the present invention, and FIG. 3 is a driving waveform diagram for explaining an LED lighting unit according to an embodiment of the present invention.

1 includes a liquid crystal display panel 100, a gate driver 102 for driving a gate line GL of the liquid crystal display panel 100, A data driver 104 for driving the line DL, a timing controller 110 for controlling the data driver 104 and the gate driver 102, A power supply unit 130, and a light source unit 152 for supplying light to the liquid crystal display panel 100.

The liquid crystal display panel 100 includes a gate line GL and a data line DL which define a pixel region intersecting with each other and a thin film transistor And a storage capacitor Cst connected in parallel with the liquid crystal capacitor Clc and the liquid crystal capacitor Clc connected to each thin film transistor TFT formed in each pixel region. The liquid crystal capacitor Clc is composed of a liquid crystal located between the pixel electrode connected to the thin film transistor TFT and the common electrode. The thin film transistor TFT is turned on by the gate-on voltage from the gate line GL to supply the data voltage from the data line DL to the pixel electrode so that the data voltage, the common voltage Vcom, So that the capacitor Clc is charged. The thin film transistor TFT is turned off by the gate-off voltage Voff from the gate line GL so that the voltage charged in the liquid crystal capacitor Clc is maintained. At this time, the storage capacitor Cst causes the voltage charged in the liquid crystal capacitor Clc to be stably maintained.

The gate driver 102 shifts a gate start pulse GSP from the timing controller 110 according to a gate shift clock GSC to sequentially turn on the power source 130 in the gate line GL. On voltage (Von) from the scan driver (not shown). The gate driver 102 supplies the gate-off voltage VOFF in the remaining period when the scan pulse of the gate-on voltage VON is not supplied to the gate line GL. The gate driver 102 controls the pulse width of the scan pulse in accordance with a gate output enable (GOE) signal from the timing controller 110.

The data driver 104 generates a sampling signal by shifting a source start pulse (SSP) from the timing controller 110 according to a source shift clock (SSC). The data driver 104 latches the pixel data RGB input according to the source shift clock SSC in accordance with the sampling signal and then latches the pixel data RGB in units of horizontal lines in response to the source output enable Supply. The data driver 104 converts the pixel data RGB supplied in units of horizontal lines into analog pixel signals using the gamma voltage from the gamma generator 120 and supplies them to the data lines DL. The data driver 104 determines the polarity of the pixel signal in response to the polarity control signal POL from the timing controller 110 when the pixel data RGB is converted into the pixel signal. The data driver 104 determines a period during which the pixel signal is supplied to the data lines DL1 to DLm in response to the source output enable signal SOE.

The gamma voltage generator 120 divides the gamma driving voltage AVDD from the power supply 130 to generate a plurality of gamma voltages according to a plurality of gradations and supplies the generated gamma voltages to the data driver 104 .

The power supply unit 130 supplies the analog gamma voltage AVDD, the common voltage VCOM, the gate-on voltage VON, the gate-off voltage VOFF, and the LED-on voltage Vcc using the digital driving voltage VDD from the TV system 170 (LON), respectively. The analog gamma voltage AVDD is supplied to the gamma voltage generator 120 and the data driver 104 and the common voltage VCOM is supplied to the liquid crystal display panel 100. The gate voltage VON and the gate- To the gate driver 102, and the LED on voltage LON is supplied to the LED lighting unit 160. [

The light source unit 152 is made up of a plurality of light source arrays (not shown) positioned on the back surface or the front surface of the liquid crystal display panel 100. Here, an external electrode fluorescent lamp (EEFL) or an LED (Light Emitting Diode) is mainly used as the light source array. The light source array of the light source unit 152 is driven by the light source driving unit 150 to generate visible light and irradiate the liquid crystal display panel 100 with the visible light.

The light source driver 150 generates a backlight on / off signal BON and BOFF to supply the driving voltage to the light source unit 152 to drive the light source unit 152 by receiving the driving voltage from the TV system 170, 152 are driven. The light source driving unit 150 supplies the backlight on / off signals BON and BOFF to the light source unit 152 and also supplies the backlight on / off signals BON and BOFF to the timing controller 110. [

The timing controller 110 controls the data driver 130 to control the data driver 130 using the vertical and horizontal synchronizing signals V and H, the data enable DE and the dot clock DCLK, Generates a signal DCS, and generates a gate control signal (GCS) for controlling the gate driver 140. The data control signal DCS includes a source shift clock SSC, a source start pulse SSP and a polarity control signal POL, and a source output signal SOE. The gate control signal GCS includes a gate start pulse GSP, a gate shift clock GSC, a gate output enable GOE, and the like.

The timing controller 110 supplies the backlight on / off signals BON and BOFF supplied from the light source driving unit 150 to the counter unit 140.

When receiving the backlight on / off signals BON and BOFF from the timing controller 110, the counter 140 counts for several seconds. In other words, when the counter unit 140 receives the backlight ON signal BON from the timing controller 110, the counter 140 outputs a high logic counter control signal CCS for 2 to 4 seconds, preferably 3 seconds, (160).

The LED lighting unit 160 emits an LED (Light Emitting Diode) instead of the lamp during the initial driving within a few seconds to solve the problem when the lamp is turned on. The LED lighting unit 160 emits the LED only for a predetermined operation time of the counter unit 140. [

The LED lighting unit 160 includes an LED switching transistor LT that is turned on in response to a counter control signal CCS of high logic supplied from the counter unit 140, , And at least one resistor (R).

Specifically, the LED lighting unit 160 turns on the LED switching transistor LT during the period in which the counter control signal CCS of high logic from the counter unit 140 is supplied, and turns on the LED switching transistor Lt; RTI ID = 0.0 > LT. ≪ / RTI >

Accordingly, the LED lighting unit 150 receives the counter control signal CCS having the high logic for 2 to 4 seconds from the counter unit 140, so that the LED lighting unit 150 receives the backlight on signal BON from 2 to 4 Lt; / RTI >

In this manner, the LED lighting unit 160 generates the LEDs for 2 to 4 seconds from the time when the LED-on signal LON is supplied from the power supply unit 130 and the backlight-on signal BON is supplied from the timing controller 110, .

The driving method of the liquid crystal display device will be concretely described with reference to FIG. 2 and FIG.

A method of driving a liquid crystal display according to an exemplary embodiment of the present invention includes the steps of supplying a driving voltage from a TV system 170 to a light source driving unit 150 and a power source unit 130, (BON) supplied from the light source driving unit 150 to the counter unit 140, and supplying the backlight ON signal BON to the LED lighting unit 160, And supplying a counter control signal (CCS) counted for several seconds from the time of receipt to the LED lighting section 160.

Specifically, the power supply unit 130 generates the LED on signal LON when the driving voltage is supplied from the TV system 170, and supplies the generated LED on signal LON to the LED lighting unit 160. The LED lighting unit 160 supplied with the LED on signal LON causes the LED to emit light.

The light source driving unit 150 generates a backlight on / off signal BON / BOFF when the driving voltage is supplied from the TV system 170 and supplies the backlight on signal BON to the light source unit 152, (110).

Then, the timing controller 110 supplies the backlight ON signal BON to the counter unit 140. [ The counter 140 outputs a counter control signal having a high logic level for several seconds for several seconds from the time when the backlight on signal BON is supplied in response to the backlight on signal BON supplied from the timing controller 110 CCS) and supplies it to the LED lighting unit 160.

The LED lighting unit 160 turns on the backlight ON signal BON by turning on the LED switching transistor LT of the LED lighting unit 160 for 3 seconds in response to the counter control signal CCS having the high logic for 3 seconds The LED will emit for 3 seconds from the point of supply.

Accordingly, the LED lighting unit 160 emits the LED for 3 seconds from the time when the LED-on signal LON is supplied and the time when the backlight-on signal BON is supplied from the timing controller 110.

At this time, when the light source array included in the light source unit 152 is formed of a plurality of external electrode fluorescent lamps (EEFL), a plurality of external electrode fluorescent lamps (EEFL) If it is applied, plasma discharge occurs and light is emitted.

Accordingly, a plurality of external electrode fluorescent lamps (EEFLs) are excited even when supplied with the backlight ON signal BON, requiring at least 2 to 4 seconds to emit light. 3, the LED of the LED lighting unit 160 can emit light for 2 to 4 seconds from the time of the backlight on signal BON, Can be improved.

Also, as described above, the present invention is not limited to the use of a large number of passive elements and active elements, and a simple circuit configuration can be realized by configuring only the LED, the LED switching transistor LT, and the resistor R.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

1 is a block diagram of a liquid crystal display device according to an embodiment of the present invention.

2 is a block diagram of an LED lighting unit according to an embodiment of the present invention and a circuit diagram of the LED lighting unit.

3 is a driving waveform diagram for explaining an LED lighting unit according to an embodiment of the present invention.

Description of the Related Art

100: liquid crystal display panel 102: gate driver

104: Data driver 110: Timing controller

120: gamma voltage generator 130:

140: counter unit 150: light source driver

152: light source unit 160: LED lighting unit

Claims (6)

A liquid crystal display panel; A gate driver for driving a gate line of the liquid crystal display panel; A data driver for driving a data line of the liquid crystal display panel; A light source for supplying light to the liquid crystal display panel; A power supply unit for generating and supplying an analog gamma voltage, a common voltage, a gate on / off voltage, and an LED on signal using a driving voltage from a TV system; A light source driver for generating a backlight on / off signal using a driving voltage from the TV system and supplying the backlight on / off signal to the light source, and supplying the backlight on signal to the timing controller; A counter unit receiving the backlight ON signal from the timing controller and generating and outputting a counter control signal having a specific logic for a few seconds from the time when the backlight ON signal is supplied; And an LED lighting unit for emitting light for a few seconds from a time point when the LED-on signal is supplied from the power source unit to a period when the counter unit is supplied with the counter control signal, thereby compensating for an initial dark period for driving the light source Display device. The method according to claim 1, Wherein the timing controller controls the gate driver and the data driver. The method according to claim 1, And the LED lighting unit emits light for 2 to 4 seconds from the time when the LED on signal is supplied. 3. The method of claim 2, The LED lighting unit An LED switching transistor that is turned on in accordance with a counter control signal of a high logic supplied from the counter unit; An LED that emits light by the LED switching transistor; And at least one resistor connected to the LED. Generating and supplying an analog gamma voltage, a common voltage, a gate on / off voltage, and an LED on signal using a driving voltage from a TV system; The light source driving unit generates a backlight on / off signal using a driving voltage from the TV system and supplies the backlight on / off signal to the light source, and supplying the backlight on signal to the timing controller; A counter receiving a backlight on signal from the timing controller and generating and outputting a counter control signal having a specific logic for a few seconds from the time when the backlight on signal is supplied; And a step of compensating for an initial dark period of driving of the light source by emitting light for several seconds from the period during which the LED on signal is supplied from the power source unit to the period during which the counter control signal is supplied from the counter unit, And a driving method of the display device. 6. The method of claim 5, And the LED lighting unit emits light for 2 to 4 seconds from the time when the LED on signal is supplied.

Images